Fix compilation with fmtlib < 8

GaudiCoreSvc/src/MessageSvc/MessageSvcSink.cpp

@@ -21,6 +21,15 @@
 #include <map>
 #include <string_view>
 
+#if FMT_VERSION < 80000
+namespace fmt {
+  template <typename T>
+  const T& runtime( const T& v ) {
+    return v;
+  }
+} // namespace fmt
+#endif
+
 namespace {
 
   /**

GaudiKernel/CMakeLists.txt

@@ -79,6 +79,7 @@ gaudi_add_library(GaudiKernel
           src/Lib/GaudiMain.cpp
           src/Lib/Guards.cpp
           src/Lib/HistoDef.cpp
+          src/Lib/HistogramArray.cpp
           src/Lib/HistoryObj.cpp
           src/Lib/IChronoStatSvc.cpp
           src/Lib/IConversionSvc.cpp

GaudiKernel/include/Gaudi/Accumulators/HistogramArray.h

@@ -11,9 +11,6 @@
 #pragma once
 
 #include <Gaudi/Accumulators/Histogram.h>
-
-#include <fmt/format.h>
-
 #include <utility>
 
 namespace Gaudi::Accumulators {
@@ -27,7 +24,7 @@ namespace Gaudi::Accumulators {
     struct FormatHistDefault {
       std::string_view text;
       FormatHistDefault( std::string_view t ) : text{ t } {}
-      auto operator()( size_t n ) { return fmt::format( fmt::runtime( text ), n ); }
+      std::string operator()( size_t n );
     };
 
     /**

GaudiKernel/src/Lib/HistogramArray.cpp

+/***********************************************************************************\
+* (c) Copyright 1998-2019 CERN for the benefit of the LHCb and ATLAS collaborations *
+*                                                                                   *
+* This software is distributed under the terms of the Apache version 2 licence,     *
+* copied verbatim in the file "LICENSE".                                            *
+*                                                                                   *
+* In applying this licence, CERN does not waive the privileges and immunities       *
+* granted to it by virtue of its status as an Intergovernmental Organization        *
+* or submit itself to any jurisdiction.                                             *
+\***********************************************************************************/
+#include <Gaudi/Accumulators/HistogramArray.h>
+#include <fmt/format.h>
+
+#if FMT_VERSION < 80000
+namespace fmt {
+  template <typename T>
+  const T& runtime( const T& v ) {
+    return v;
+  }
+} // namespace fmt
+#endif
+
+std::string Gaudi::Accumulators::details::FormatHistDefault::operator()( size_t n ) {
+  return fmt::format( fmt::runtime( text ), n );
+}

GaudiKernel/src/Util/genconf.cpp

@@ -69,6 +69,15 @@
 #include <type_traits>
 #include <vector>
 
+#if FMT_VERSION < 80000
+namespace fmt {
+  template <typename T>
+  const T& runtime( const T& v ) {
+    return v;
+  }
+} // namespace fmt
+#endif
+
 namespace po = boost::program_options;
 namespace fs = boost::filesystem;